1. Field of the Invention
The present invention relates to an aircraft docking guidance system which provides pilots of taxing planes with data concerning distance and azimuth (direction) during movement across airport aprons to the parking spot. More particularly, this invention relates to an aircraft docking guidance apparatus for calculating a deviation from an approach line and a distance from a stop point to the nose gear in a parking spot by using a picked-up image of an anti-collision light (ACL) located on the upper fuselage of all aircraft as a position reference, and visually displaying the calculation results to a pilot as azimuth (direction) information and distance information by means of a display unit on the ground, thereby accurately guiding the aircraft from airport aprons to the parking spot.
2. Description of the Related Art
A conventional aircraft docking guidance apparatus is designed to provide azimuth (direction) and distance information by utilizing an optical technique. In this technique, however, since the parallax varies among pilots depending on the loading capacities of aircraft, sufficiently precise azimuth (direction) information cannot be obtained.
More specifically, in the conventional technique, of various types of schemes, azimuth (direction) information is obtained by mainly using the parallax of a pilot by optical applications, and a deviation from an approach line is displayed on a display unit installed on the ground. For this reason, proper azimuth (direction) information can be obtained at the captain's seat, but cannot be obtained at the co-pilot's seat. That is, only the captain can pilot the aircraft.
In the conventional technique, distance information is obtained by mainly using a sensor buried underground below an approach path. According to this technique, when the passage of wheels of an aircraft is detected, a remaining distance is displayed on a display unit. In this distance information display technique, however, the installation and maintenance of this sensor interfere with flight operations of aircraft.
Furthermore, in the above-described azimuth and distance information display techniques, it is difficult to control different types of aircrafts with respect to the sam parking spot.
As another guidance technique, a distance measurement technique based on a laser is available. This technique, however, can only be applied to limited types of aircracts, because the reflectivity of a laser beam with respect to dark colors is low. In addition, it is difficult to properly use this technique in all kinds of weathers.